Pumps accommodated in a substantially closed, e.g. cuboid, container are already known which also house accessory units of the pump. The advantage of such known pump stands consists essentially in that they are accommodated in a self-contained or closable, case-like enclosure together with the associated accessory units. Among the disadvantages displayed by this type of pump stand with closed container is that such pump stands cannot be easily adapted to the different requirements of the users. They are therefore often equipped with numerous parts complementing the pump of the pump stand, such as vacuum controller, control unit, trap or the like, even though these parts are not needed in a particular instance. Accordingly, such substantially box-like pump stand containers are relatively elaborate and costly and not very adaptable to varied requirements.
Pump stands are also already known which carry the pump in an open state on a base plate to be selected and have accessory units for the pump simply mounted around the latter. The advantage of this type is the simplicity with which the respective accessory unit(s) required can be selected and added. Even relatively large accessory units, such as traps for exhaust vapor condensate for example, may also be retrofitted to the base plate. Major drawbacks of such an open pump stand include, inter alia:
Control parts are, as a rule, only associated with the respective accessory unit, so that any different, separate control units must be housed on a "home-made board". These then also include various, different electrical, hydraulic or pneumatic connecting lines. A drawback in this connection is that these connecting lines often lie open on the base plate or must be fixed there in an open state. In practice, they are also in the way during operation of the pump stand, and they lack the protection they would have in the above-mentioned, container-like pump stand.